In the simulation, the Moon goes through a cycle of phases over the course of a month. It starts as a new moon, where it cannot be seen in the sky at all. As the days progress, the Moon appears to grow larger and goes through phases such as waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, and finally waning crescent. The cycle then repeats itself, with the Moon appearing to decrease in size as it goes through the waning phases. This pattern of changes in the Moon's appearance over the course of a month is known as the lunar cycle.
